This article is an excerpt from Sports Nutrition for Endurance Athletes by Monique Ryan MS, RD, LDN, CSSD. In her comprehensive guide to sports nutrition, Ryan uses her 30 years of experience coaching professional and age-group athletes to simplify this complex subject into proven, real world guidelines. Sports Nutrition for Endurance Athletes shows runners, cyclists, and triathletes how to address specific nutritional needs for short- and long-course racing and busts dozens of myths and misconceptions along the way.
Reading labels of sports drinks and making sense of the various carbohydrate sources can be confusing. Following is a list of various carbohydrate sources and combinations provided in many commercial sports drinks:
Glucose: A simple carbohydrate that can be absorbed at the rate of 1g per minute or 60g per hour.
Maltodextrin: Often referred to as glucose polymers, which are long chains of glucose molecules. It does not offer any absorption advantages over glucose but often has a milder taste. May be promoted as a “complex carbohydrate,” but it is still a manufactured carbohydrate with a high glycemic index.
Fructose: A simple carbohydrate often added as a second carbohydrate source to sports drinks. Usually not used as the sole or main carbohydrate amount in sports drinks. May not be tolerated in large amounts by athletes who have a fructose intolerance.
Glucose-fructose combination: Appears to be the most effectively absorbed carbohydrate mix, as several transport mechanisms can be used simultaneously. Generally drinks provide a 2:1 glucose:fructose ratio. Absorption is at 1.5g per minute or up to 90g per hour, an amount that favors fueling for longer events.
Glucose-sucrose combination: Essentially fuels like a glucose-fructose combination, as sucrose is a two-molecule carbohydrate that breaks down into glucose and fructose.
See what to eat and when with Sports Nutrition for Endurance Athletes. Ryan demystifies optimum daily nutrition and shows simple steps to make the best decisions about what you eat and drink.